Spontaneous CP violation in the next-to-minimal supersymmetric standard model revisited

Gustavo da Fonseca Castelo; Frank Kruger; Jorge C. Romão; Ana Margarida Domingues

Key information

Authors:

Gustavo da Fonseca Castelo (Gustavo da Fonseca Castelo Branco); Frank Kruger; Jorge C. Romão (Jorge Manuel Rodrigues Crispim Romão); Ana Margarida Domingues (Ana Margarida Domingues Teixeira)

Published in

July 2001

Abstract

We re-examine spontaneous CP violation at the tree level in the context of the next-to-minimal supersymmetric standard model (NMSSM) with two Higgs doublets and a gauge singlet field. We analyse the most general Higgs potential without a discrete Z3 symmetry, and derive an upper bound on the mass of the lightest neutral Higgs boson consistent with present experimental data. We investigate, in particular, its dependence on the admixture and CP-violating phase of the gauge singlet field, as well as on tan beta. To assess the viability of the spontaneous CP violation scenario, we estimate epsilonK by applying the mass insertion approximation. We find that a non-trivial flavour structure in the soft-breaking A terms is required to account for the observed CP violation in the neutral kaon sector. Furthermore, combining the minimisation conditions for spontaneous CP violation with the constraints coming from K0-bar K0 mixing, we find that the upper bound on the lightest Higgs-boson mass becomes stronger. We also point out that the electric dipole moments of electron and neutron are a serious challenge for SUSY models with spontaneous CP violation.